FIGS. 1, 2 and 3 illustrate a prior art hydrodemolition apparatus 10 for removing materials from horizontal surfaces. A nozzle carrier 12 is mounted within a laterally-extending, generally rectangular frame 14 to reciprocate transversely (16) to the direction of the direction of travel 18 of the machine. Reciprocation of the nozzle carrier 12 is along frame members 22, 24 of the frame 14. Nozzles 26, 28, 30 extend downward from the nozzle carrier 12 through gaps 32, 34, 36 between laterally-extending elongated base frame members 38, 40, 42, 44 to work the underlying road or deck surface. The front 46 and sides 48 of the frame extend down to near contact with the surface such that there is little opportunity for debris to escape from those sides. The rear of the frame is covered with a skirt 50 to prevent the scattering of debris through the gap created between the bottom of the frame and the partially excavated surface.
The presence of a gap between the frame members to accommodate the movement of the nozzles as the nozzle carrier reciprocates transversely provides a means for debris to be ejected vertically through the gaps for those portions of the gaps not otherwise covered for the time being by the nozzle carrier itself. It is therefore known in the prior art to provide elongated rubber slats 52, 54, 56, 58, 60, 62 extending lengthwise of the frame between the gaps. They are secured by retention plates 64, 66, 68, 70. The sides of the slats meet or overlap slightly (as at 72) over the gaps to close the gaps except where a nozzle protrudes through the adjoining slats. The adjoining slats form elongated slots 74, 76, 78 overlying the elongated gaps 32, 34, 36. Despite that, debris is still occasionally ejected from the slot presenting a danger to surrounding equipment and personnel.
It is an object of this invention to further reduce the opportunity for debris to be ejected vertically through the gap in the frame members.
These and other objects of the invention will be better understood by reference to the detailed description of the preferred embodiment which follows. Note that the objects referred to above are statements of what motivated the invention rather than promises. Not all of the objects are necessarily met by all embodiments of the invention described below or by the invention defined by each of the claims.